Re: Hydrostatic head
Posted: 6 Apr 2022, 8:22am
If you think about the traditional cotton canvas fly on a Force 10 which relies on surface tension as much as formal waterproofing to keep the inner dry it should be pretty clear that Gore-Tex-like HHs aren't really relevant in a tent fly in the same way they are in a jacket.
I suggest that you try out the tent in yours or someone’s garden in heavy rain before an expedition!
While it's entirely likely such a tent will wear out before something made of sterner stuff, until that time there's the carrying half the weight and two thirds of the bulk thing. It's a trade off.
My personal reservation about very light fabrics is mainly down to the groundsheet, and that's not it being waterproof as simply so thin as to be a major condensation trap given half an excuse. You can get round a lot of that with a footprint, but that does blow a bit of a hole in the weight/bulk advantage.
But Big Agnes and MSR wouldn't sell that many tents year on year if they leaked copiously at the first sign of heavy rain. They don't. Back in the day the main paranoia was if you didn't have a Quasar or a Force 10 you'd obviously have your tent flattened regularly as storms can happen at any time of year, so lots of people wandered about the place with > 4 Kg of tent just in case there was a proper blow. And then it turned out that you don't need storm proofing fit for an 8000m peak and people stopped doing that, but the new FUD seems to be hydrostatic head... While more may be better, it remains the case that enough is enough.
Having said that, pitching any tent in a storm before you put it to an acid test is a good idea. No QA process is perfect, but you're looking for niggles, not fundamental cluelessness on the part of the designers to select a workable fabric.
Pete.